Authorities found bomb-making material at the rural home of a man accused along with his son of killing two law enforcement officers in an explosion at a bank, a court document released Thursday says.

Some of the material found at Bruce Turnidge's home matched that used in the bomb that killed the officers and critically injured a third Dec. 12, the probable cause statement said. It also said some of the material was found in a nearby stream, with fresh foot and tire tracks leading to it.

The document says the search turned up two tubes of the explosive Tovex, which manufacturer Web sites say is a replacement for dynamite used in mining and excavating. Bruce Turnidge in the past has worked as an excavator.

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Other items turned up in a search of Turnidge's home and shop and the nearby stream were angle iron, sheet metal, metal grating, bolts, wiring and plywood with green spray paint matching the color of a metal box containing the bomb that exploded at the West Coast Bank in Woodburn, the document said. Several of the items matched materials used in the bomb, the document said, but aside from the paint it did not say which items matched.

The document said U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives agents believed "some type of black or smokeless powder was used in the fabrication" of the West Coast Bank bomb.

State Police bomb technician William Hakim and Woodburn police Capt. Tom Tennant were killed in the blast. Woodburn police Chief Scott Russell lost a leg and is listed in critical condition.

Turnidge, who appeared in court for the first time Thursday, is charged with his son, Joshua, who appeared in court Tuesday. A lawyer for Bruce Turnidge, John Storkel, declined to comment after the court appearance.

Neither the 57-year-old father nor his 32-year-old son has entered a plea to charges that include aggravated murder; both now have court-appointed attorneys, are being held without bail, and are to return to court Dec. 26.

Authorities have not said what they believe the motive of the bombing was.

A caller had threatened a bank next door to the West Coast Bank the day of the bombing. Investigators found a package they determined to be a hoax explosive device at that bank, then found the green box as they continued searching the area. A bank employee reported seeing Hakim trying to open the box while Tennant held it when the bomb exploded.

Joshua Turnidge, a former Navy serviceman, was arrested Sunday at his home in Salem; his father was arrested Tuesday near Jefferson about 15 miles south, the day the rented home was searched.

An officer said in the document released Thursday that he overheard Joshua's girlfriend telling Bruce Turnidge on the telephone Sunday that officers had inquired about welding equipment and barrels.

When they arrived at the farm home Sunday night, Bruce Turnidge was gone, and his wife said he had gone for a walk on what officers noted was a "cold, dark, snowy" night, the document said.

He returned "several hours later, offering no explanation for his sudden disappearance," it said.

The search on Tuesday also turned up a badly burned laptop computer, welding machinery and a blasting cap, the document said.

Click here for more on this story from FOX affiliate KPTV.com in Portland.